1. Technical Field
The present invention relates to an electrooptic device suitable for use in displaying various information.
2. Related Art
Techniques for reducing the size and weight of electrooptic devices have been developing in the last few years. Portable phones and portable digital assistants (PDAs) also use liquid-crystal display devices and are therefore their size and weight reduction has been tried.
Liquid-crystal display devices principally include a liquid-crystal display panel constructed of two opposing substrates made of glass or the like and liquid crystal sandwiched by the two substrates and an illumination system including an optical waveguide having a light source such as a light emitting diode (LED) at the end. The liquid-crystal display panel has, for example, a polarizer bonded to the upper and lower surfaces of the two substrates.
The two substrates of the liquid-crystal display panel have become thin in recent years as liquid-crystal display panels have decreased in thickness. Accordingly, the liquid-crystal display panel is prone to have an uneven gap because of the pressure applied when the polarizer is bonded to the liquid-crystal display panel. For example, the layer of the adhesive (hereinafter, simply referred to as an adhesive layer) sometimes becomes uneven in thickness, depending on the position of pressure when the polarizer is bonded to the liquid-crystal display panel. In this case, Newton's rings are generated around the position of the display screen where the adhesive layer has become thin by strong pressure. Such uneven gap has increasingly become conspicuous as recent liquid-crystal display panels have increased in contrast. JP-A-07-105781 describes a technique for preventing the generation of Newton's rings by bonding a touch panel to a surface supporter that covers the liquid-crystal display panel with acrylic adhesive tape.
The adhesive layer used in the technique described in JP-A-07-105781 may be thicker than 50 μm because tape adhesive is used. However, it is preferable that the adhesive layer be 50 μm in thickness as liquid-crystal display panels have become thin.